this guy that use to rebuild trannys said that those 700r4s only last up to 50k-60k and the turbo 350s are bullit proof. is this true
cuz i love my 7090r4 cuz of the over drive u know 1600rpms at 65mph. and if i do go to turbo 350 is there any major mods i need to know about. also is there different gear ratio between the two. and what are the rpms at 60. i have the stock rear end.

I wonder how my 700r has 165,000 with no rebuild, with only a transgo shift kit and fluid cooler added. It shifts firm as well, no slippage. If built right they can handle alot. But like ANY transmission you abuse it. somethings gonna give.

If you go to th350 you have to get a torque arm bracket, either B&M or Hurst.

I switched from the 350 turbo to the 700R4 this past spring just because of the overdrive. The turbo 350 was great trans but as for cruising with 3.73 gears was awful, RPM's were high at freeway speeds and you could watch the gas gauge drop as the tach was up. The 700R4 I got is built with heavy duty everything fromTPI Performance trans and I am having a ball with the car now. This thing rips, breaking the tires loose with the 2-3rd and will bark the tires going into overdrive when I have my foot in it. Just as the old saying goes, you get what you pay for, and you need to deal with someone knows their stuff. JMO and 2 cents worth..

The 700r4 evolved from the turbo 350. The back (internal) half is almost identical and even shares some pieces of the 350. I have been running a 700 for 15 years and 279k miles. It has survived stock down to high 10 sec et's. I am on my third one . People keep saying they are junk and I keep picking up the old cores and running with them. When put together carefully they are good transmissions that can hold up to some reasonable power.
*I* would never remove mine to install a non overdrive unit. This applies to my street car. If I had a racecar, it would likely have something different.

I've seen plenty 700R4's last longer than 50k-60k miles. I've personally driven 4 of them with over 100K miles still OEM internals. Yes they do break but if you do some mods to them early in their life you can extend their life alot. Tranny cooler to battle heat and a shift kit to raise line pressure and you're set. Stock 700R4's suck. Modded ones dont. I'm currently running a TH350 in my IROC-Z, still all stock and strong as heck. Definately stronger stock vs stock. But driving on the freeway sucks with no OD, 700R4 definately has the advantage there.

mine took a crap at 69,000 miles but otherwise i hear good things about them.

well.... my camaro had the tranny rebuilt before bought it, and now it just went out after 2 years since the rebuild.but my car has 266,XXX miles on it though, and no tranny cooler and i just about floored it every chance i got.

mine has 142k on the stock internals with no upgrades and it still shifts like new . I plan to have mine rebuilt over summer or fall, which should handle all the power i'll be throwing at it with ease.

My 1990 has 190,000 with all stock internals and no rebuilds that I know of - the last 75,000 are all mine, and with no troubles.

My 1992 has 150,000 miles, and it seemed fine before my 350 swap. After the swap, it slips. BUT - the 1992 was previously owned by a teen that abused it. I found a shift kit inside, although it didn't shift any firmer than stock behind the 305. It's obvious from the $900 invoice I later found under the seat that he had a slipping problem, and a tranny shop took him for a rebuild fee when all they did was install a shift kit to firm it up a bit. Now my 350 slips it pretty good.

Like anything else - It just depends on who did what to it when, as to how well it works.

yeah mine's taking a crap on me now at 112k...I am looking around now for either a T-5 conversion or just upgrading to a 4L60E transmission from 93+ Fbodies cause those actually take a beating and hold their ground well.

Kinda disappointing cause I heard the avergae lifespan of these trannies is like 160k miles. I'd figured that I would've sold the car by then if that had been the case but.

I guess not...

Jeez man complaining won't help you any seriously take the other guys advice, take it to a shop have the tranny flushed and filter changed, then have them check the tv cable for adjustment. You must be one of the very few people who've not experienced problems in cars with 100k miles or less on them.

Basically you don't know what's wrong with it, yet these guys telling you this stuff didn't tear it apart and physically see a burnt 3-4 clutch pack. I'd pull your tranny dipstick out and check for discoloring/burnt smell if it's good then it's most likely a tv cable adjustment. I've found myself very lucky to not have problems with a car with 112k miles on it.......

I paid over 3k for my car and have put 700$ in it so far with just misc. repairs this doesn't include tires, drivetrain or engine work, just normal old up keep and wear parts. No big deal if it's broke and you can't afford to have it rebuilt check in to buying 1 off these boards for cheap, they sell reasonably all the time. If that's a no go check on ebay 600$ or less for a new 700r4 it's not horribly bad.

Cant be but so bad considering that my friends has 208,000 miles on it with stock internals and he maually shifts it every time he stops and takes off.

700R4 = 4L60 same thing

4L60E = computerized tranny (hence the "E" (electronic) at the end of the 4L60)

4L60E = no more TV cable. BUT - The 3rd gen doesn't have the computer for it, which means almost $2000 in aftermarket electronics and conversion parts just to install once you get one! Check thread by Bruce Embry - he's installing one now and has costs associated with it.

Used 700R4's are a cheap alternative - especially ones from cars not abused (ie granny's Caprice or Uncle Joe's van) - I've seen plenty around here for $500-$600, and a few closer to $300.

A rebuild? I was quoted $1200 for a stock rebuild on mine locally - screw that! Nicely built 700R4's that can handle decent power with nice internals can be had for $1500!

And if it's just the 4th gear change - ride it awhile longer while you save. Hell, by the time my LO3 RS gets to the 4th gear shift with my foot in it, I'm close to 60mph - if I still have my foot in it hard by then, I'm sure to get a ticket - given that 90% of my driving is in 45mph zones! Baby her for a few months, and save some cash if a new tranny is needed.

In a daily driver, and on a daily basis, a hard 4th shift = a ticket that I can live without! LOL

Well I'm not installing any more, ITS INSTALLED. The complete installaton went pretty smooth except for a few hipcups. As for cost, I don't think you can beat the deal that I got. I have an heavy duty 4L60e new from GM Performance Parts with an 12,000Mile/1 year warrenty. I paid $1095 for the transmission and the controller through Summit was $659.95...... I also had to get one of those Cable-X units and new electronic cruise control. The total for the electronics including TCI's TCU, the Cable X and Cruise control was less then $1200.

I had other costs associated with the install due mainly to the updates required to install the transmission into the car. For someone who already has an 700r4 in the car, they would not have to do some of these updates.

There are some advangages with going with the 4L60e and TCI's TCU controller; adjustable shift points(up/down shifts, WOT), adjustable pressures, manual shift inputs, performance/econ input mode selection, etc. .......

I have had about 4 diferent vehicles with the 700r4, 2 of them in full size trucks. Only one had to be rebuilt (at 112,000 miles) and I paid $795 to have rebuilt. After the rebuild the truck pulled a 6000# trailer everywhere it went for another 70,000 miles with no problem. I sold the truck to a guy I know who put a new motor in the truck and a goose neck hitch and now pulls cattle with it and no problems. So this truck now has something close to 140,000 miles on the rebuilt tranny that pulled a trailer all the time with no problems.
My wife has a 4l60e in her Envoy and I hate it. The shifts are not near as firm as in my camaro. The best shifting trany I have ever had is the alison tranny in my current truck. I would have never thought a automatic tranny could behave so much like a manual in the fact thats it's always in the gear I would have it in if it was a manual.

That guy that used to rebuild trannys is an idiot.

700r4s if taken care of can last alot longer than 60-70K even when pushed alot. If any stock transmission took a beating it was my 1983 700r4, the supposed worst year for the 700r4. It had the smallish 27 spline input shaft even. My dad owned my Van before me, he put over 300,000 miles on it, frequently towing a trailer behind it, left it in OD and just went. He had the fluid changed every 50,000 and left it at that(had the factory tow package and therefore the large external cooler). I put another 40,000 on it without any problems. When I rebuilt the 350 and put the LT1 cam into it, I quickly killed it. Ended up building the 700r4 that went into it, 2 more times in 5,000 miles due to slippage from inadequate line pressure burning up the frictions. (Tuned TBI and improper valvebody calibration fixed by a Bowtie Overdrive TV correction kit for a BBC TBI). Also added a bunch of trick parts for firming up the shifts, increasing the line pressure, increasing the holding power of the clutches, Billet 2-4 servo, .500 boost valve, corvette sleeve and plunger, etc.

I am now at about 368,000 and everything is doing great (Knockin on Wood)

My uncle had a 1994 chevy truck with over 250,00 on the original 4L60E when he got rid of it, still shifted great.

My aunt has a 1997 Yukon with almost 200,000.

My dad has a 1997 G1500 with almost 180,000 on the original 4L60E (had to get the TCC regulator valve redone and the torque converter changed at about 45,000 to cure a P1810 code).

My 1987 GMC Jimmy has 215,00 on it before switching to the 3.4 Turbo and killing the original 700r4.

I know of numberous other high mile 700r4/4L60(E) that have high mileage on them.

To the original poster's question about gear ratios, the 700r4 has a 3.06 first gear, whereas the TH350's is around 2.50, so you actually get a lot more grunt out of the hole with a 700r4. I have two buddies that grenaded their 700r4's, but they both beat on their cars unbelievably hard. I mean an autistic/hyperactive 16 year old would drive mellow compared to these two guys! One of the above mentioned two guys has also blown up three rear ends to boot. In fact, the same guy put in a TH350 after he blew up the original trans, and he killed that tranny as well. As for my 700r4, it just turned over 220,000 miles and still shifts nice and firm. It has all stock internals, except for a B&M upshift valve, and all I've ever done to it is change the fluid and filter about every 50,000 miles. So personally, I really can't cap on 700r4's too much based on my own experiences with them.

I think 700s get a bad rap because for ALL OUT racing a TH350 is the better choice. For the same money a 350 is a lot cheaper and simpler to rebuild every season.

But most of us that drive on the street don't have more than 400hp and dont have to do a rebuild every year.

I just got back from a long trip and averged 22.3 mpg with 3.73 gears going 75 mph the whole way. Try getting that kind of mileage with a TH350.